Agricultural harvesters, such as agricultural combines, are designed to travel through agricultural fields harvesting crops. Agricultural combines receive crop severed from the ground and convey it to threshing, separating and cleaning devices within the agricultural combine.
In a typical arrangement, the agricultural harvesting head severs the crop from the ground and conveys it to the central region of the harvesting head where it is then conveyed rearward into a central and forwardly opening aperture in the front of the agricultural combine proper.
Agricultural harvesting heads are quite long, on the order of 10-15 m in overall length. In order to accurately follow the contours of the ground and sever crop at the appropriate point on the stem, agricultural harvesting heads have been made in sections that are generally hinged with respect to each other. A typical agricultural harvesting head of this type is formed in two or three sections that are pivotable with respect to each other. They pivot with respect to each other about a generally horizontal and fore-and-aft extending axis. Thus, a two section agricultural harvesting head would have one pivot axis, and a three-section agricultural harvesting head would have two pivot axes.
In the past, simple pivots or hinges were provided to permit the sections to pivot with respect to each other.
See, for example U.S. Pat. No. 9,198,353 (B2). In the '353 patent, a left frame section and a right frame section are hinged to a wide center frame section. Both the front pivot joint and the rear pivot joint between the frames are located off to one side of the center frame and away from the central aperture in the center frame through which cut crop passes during operation.
In another arrangement (U.S. Pat. No. 6,675,568 B2) the agricultural harvesting head is a draper head having three frame sections (a center section, a left wing section and a right wing section). In this arrangement each of the wing sections are hinged with respect to the center section about two pivot joints with pivot pins (see: FIG. 6, items 17H, 27; FIG. 20, items 71A, 71B). In this arrangement, the pivot joints define a pivot line that is disposed outboard of the center frame and outside of the central aperture in the center frame through which cut crop is transmitted during operation. The wing sections pivot with respect to the center section about these pivot joints.
To provide space for other mechanical elements and/or crop flow at the rear of the agricultural harvesting head, it would be beneficial to eliminate the simple hinge joint/hinge pin arrangement at the rear of the harvesting head, yet still constrain the two frame sections to pivot about a generally forward extending axis. It is an object of this invention to provide these advantages in one or more of the embodiments described in one or more of the claims below.